1. Field of the Invention
The present invention relates to a ceiling-mounted TV support, and more particularly to a transmission assembly for a ceiling-mounted TV support. The transmission assembly has a gear assembly securely provided on a fixing plate attached to a rooftop and driven by a motor, a first guiding gear mated with a second guiding gear rotatably mounted on a moving plate with an LCD screen and a memory chip mounted by the gear assembly to store in a memory the rotation angle of a second gear of the gear assembly to automatically shut off the power to the motor when the screen is in position.
2. Description of Related Art
With the introduction of Recreation Vehicles (RV), people have become more and more interested in ways to spend their leisure time. People do not want any stress or trouble in their holidays, so everything involved in the holidays should be easy to operate and trouble-free. One of the luxury items that goes with the RV is the TV set. The TV set normally is mounted in the ceiling of the RV and can not be adjusted according to different requirements. Therefore, users will have to adjust themselves to the angle of the TV set, which is quite troublesome. Moreover, even when the angle of the TV set is adjustable, users still have to gradually adjust the angle manually for viewing in the most comfortable posture. To overcome the aforementioned problems, a transmission assembly is introduced into the market to save the viewers the trouble arising from adjustment. The transmission assembly mounted on a bottom plate (70), as shown in FIG. 6, has a motor (71), a gear assembly and a rack (60).
The motor (71) has a worm (not shown) connected with a worm gear (73). The gear assembly has a first transmission gear (74) fitted beneath the worm gear (73), an axis (75) extending through the worm gear (73) and the first transmission gear (74), a second transmission gear (76) mated with the first transmission gear (74), a third transmission gear (77) securely engaged with the second transmission gear (76) and a fourth transmission gear (78) mated with the third transmission gear (77). Due to the mutual relationships of the gear assembly, the driving force from the motor (71) is able to drive the rack (60) to thus move the LCD screen to a predetermined angle.
This kind of arrangement does have the effect to control the movement of the LCD screen, however, when the LCD screen reaches its predetermined angle, the motor (71) still outputs power to the gear assembly and accordingly to the rack (60), which will eventually damage the gear assembly. Although this kind of transmission assembly is able to move the LCD screen, the user still needs to manually adjust the angle of the TV every time for the most comfortable posture for watching the TV.
To overcome the shortcomings, the present invention tends to provide an improved transmission assembly for a ceiling-mounted TV support to mitigate and obviate the aforementioned problems.
The main objective of the invention is to provide an improved transmission assembly having a safety device provided in a gear assembly of the transmission to prevent damage to the gear assembly.
Another objective of the invention is to provide a first guiding gear rotatably mounted on a fixing plate and a second guiding gear rotatably mounted on a moving plate and mated with the first guiding gear. The first guiding gear and the second guiding gear are so mated that the movement of the moving plate is able to be controlled precisely.
Still, another objective of the invention is to provide a memory chip mounted beside the gear assembly for sensing the rotation angle of the gear assembly to automatically shut off the power to the motor.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.